Renee Zellweger has credited a massive lifestyle change for her drastic new look after she shocked fans with her altered appearance at a Hollywood event on Monday.

The Bridget Jones's Diary star hit headlines and became a trending topic on Twitter.com after she made her first public appearance in months at the Elle Women in Hollywood Awards in Los Angeles, sparking debate over her 'new face'.

Zellweger has now opened up about the massive change, revealing she was not taking care of herself properly for many years and has now adopted a healthier lifestyle after taking a step back from Hollywood.

She tells People.com, "I'm glad folks think I look different! I'm living a different, happy, more fulfilling life, and I'm thrilled that perhaps it shows... My friends say that I look peaceful. I am healthy. For a long time I wasn't doing such a good job with that. I took on a schedule that is not realistically sustainable and didn't allow for taking care of myself. Rather than stopping to recalibrate, I kept running until I was depleted and made bad choices about how to conceal the exhaustion.

"I was aware of the chaos and finally chose different things... I did work that allows for being still, making a home, loving someone, learning new things, growing as a creative person and finally growing into myself...

"People don't know me in my 40s... People don't know me (as) healthy for a while. Perhaps I look different. Who doesn't as they get older?... But I am different. I'm happy."